Partially Foam Encased Pocketed Spring Assembly

Abstract

A partially foam encased pocketed spring assembly is made in a fully automated assembly machine. A first foam rail is introduced into the assembly machine and glued to upper and lower substrate webs. A first string of pocketed springs is then glued to a side surface of the first foam rail between upper and lower substrate webs and glued to the upper and lower substrate webs. Additional strings are joined together to create a pocketed spring interior. A second foam rail is then introduced into the assembly machine and glued to an outer string and to the upper and lower substrate webs to create a core. Third and fourth foam rails are glued to the core.

What is claimed is: 
     
         1 . A partially foam encased pocketed spring assembly comprising:
 a lower substrate sheet;   an upper substrate sheet;   first and second foam rails glued to the upper and lower substrate sheets at opposed ends of the partially foam encased pocketed spring assembly;   a first string of pocketed springs glued to the first foam rail and extending parallel to the first and second foam rails;   a last string of pocketed springs glued to the second foam rail;   interior strings of pocketed springs glued to each other between the first and last strings of pocketed springs; and   third and fourth foam rails glued to the upper and lower substrate sheets on opposed sides of the partially foam encased pocketed spring assembly.   
     
     
         2 . The partially foam encased pocketed spring assembly of  claim 1 , wherein the lower substrate sheet is thicker than the upper substrate sheet. 
     
     
         3 . The partially foam encased pocketed spring assembly of  claim 1 , wherein at least two of the foam rails have the same cross-sectional configuration. 
     
     
         4 . The partially foam encased pocketed spring assembly of  claim 1 , wherein each of the foam rails is made of polyurethane foam. 
     
     
         5 . The partially foam encased pocketed spring assembly of  claim 1 , wherein the lower substrate sheet has a different thickness than the upper substrate sheet. 
     
     
         6 . The partially foam encased pocketed spring assembly of  claim 1 , wherein each of the third and fourth foam rails is glued to the first and second foam rails. 
     
     
         7 . The partially foam encased pocketed spring assembly of  claim 1 , wherein an end surface of each of the first, last and interior strings is glued to the third and fourth foam rails. 
     
     
         8 . A partially foam encased pocketed spring assembly comprising:
 a lower substrate sheet;   first and second foam rails glued to the lower substrate sheet;   a pocketed spring interior comprising strings of pocketed springs attached to each other and to the lower substrate sheet, a first string of pocketed springs being glued to the first foam rail and a last string of pocketed springs being glued to the second foam rail, the strings extending parallel to the first and second foam rails; and   third and fourth foam rails glued to the lower substrate sheet.   
     
     
         9 . The partially foam encased pocketed spring assembly of  claim 8 , wherein each of the third and fourth foam rails is glued to the first and second foam rails. 
     
     
         10 . The partially foam encased pocketed spring assembly of  claim 8 , further comprising an upper scrim sheet, wherein the lower substrate sheet is thicker than the upper scrim sheet. 
     
     
         11 . The partially foam encased pocketed spring assembly of  claim 8 , wherein at least two of the foam rails has the same cross-sectional configuration. 
     
     
         12 . The partially foam encased pocketed spring assembly of  claim 8 , wherein each of the foam rails is made of polyurethane foam. 
     
     
         13 . The partially foam encased pocketed spring assembly of  claim 8 , wherein each of the strings is the same length along with the first and second foam rails. 
     
     
         14 . The partially foam encased pocketed spring assembly of  claim 8 , wherein an end surface of each of the first and second foam rails is glued to the third and fourth foam rails. 
     
     
         15 . A partially foam encased pocketed spring assembly comprising:
 a lower substrate sheet;   an upper substrate sheet;   first and second foam rails attached to the lower substrate sheet and upper substrate sheet;   a pocketed spring interior comprising strings of pocketed springs attached to each other, a first string of pocketed springs being attached to the lower substrate sheet and the upper substrate sheet and a last string of pocketed springs being attached to the lower substrate sheet and the upper substrate sheet, the strings extending parallel to the first and second foam rails; and   third and fourth foam rails attached to the lower substrate sheet and the upper substrate sheet, each of the third and fourth foam rails being attached to the first and second foam rails.   
     
     
         16 . The partially foam encased pocketed spring assembly of  claim 15 , wherein the first string of the pocketed spring interior is attached to the first foam rail and the last string of the pocketed spring interior is attached to the second foam rail. 
     
     
         17 . The partially foam encased pocketed spring assembly of  claim 15 , wherein the lower substrate sheet is thicker than the upper substrate sheet. 
     
     
         18 . The partially foam encased pocketed spring assembly of  claim 15 , wherein each of the foam rails has the same cross-sectional configuration. 
     
     
         19 . The partially foam encased pocketed spring assembly of  claim 15 , wherein each of the foam rails is made of polyurethane foam. 
     
     
         20 . The partially foam encased pocketed spring assembly of  claim 15 , wherein each of the strings is the same length as the first and second foam rails. 
     
     
         21 . A partially foam encased pocketed spring assembly comprising:
 a lower substrate sheet;   first and second foam rails attached to the lower substrate sheet;   a pocketed spring interior comprising strings of pocketed springs attached to each other, a first string of pocketed springs being attached to the lower substrate sheet and a last string of pocketed springs being attached to the lower substrate sheet, the strings extending parallel to the first and second foam rails; and   third and fourth foam rails attached to the lower substrate sheet, each of the third and fourth foam rails being attached to the first and second foam rails.   
     
     
         22 . The partially foam encased pocketed spring assembly of  claim 21 , wherein the first string of the pocketed spring interior is attached to the first foam rail and the last string of the pocketed spring interior is attached to the second foam rail.